SU1509142A1 - Method of hot rolling of strips and sheets - Google Patents

Abstract

The invention relates to rolling production, and more specifically to the manufacture of strips and sheets on wide-strip hot rolling mills (PSSGP) with a reversible vertical stand in the roughing group and on reversible sheet mills. The purpose of the invention is to expand the technological capabilities of the vertical cage and increase the yield of rolled metal by reducing the face cut. Continuously cast billets are rolled to the required cross-section in a rough ShPSGP group with a reversible vertical cage in the following sequence. Pre-profiling of the ends across the width is carried out by squeezing the narrow edges with locked (non-rotating) vertical rolls. Before each pass, only the front end of the roll on the length of the gripping arc is profiled, compressing it by an amount equal to the total reduction of the main part of the roll in width in two subsequent passes, and before the last pass - by the amount of reduction in this pass. In order to implement the method, the vertical stand must have a pressure hydraulic device and a lifting roller table with the possibility of moving the roll in a vertical plane to ensure deformation at two levels of rolling, from which the front ends are profiled at one level and the main part of the roll is reduced at the same level. narrow gran

at the same time, on one of the rolls of the vertical stand, (the other, their working part is smooth) equal to half the barrel length, at least one piece with a flat surface, the length of which is 1.2-1.5 times the maximum arc length capture when rolling. After obtaining a given width in the cage with vertical rolls, the roll goes into the rough and finishing groups of GPRSGP to be reduced to a final size. The use of the method allows to increase the mill productivity by profiling the ends in a vertical stand without using a horizontal press for these purposes and to reduce the specific metal consumption by 8-10 kg per 1 ton of finished steel. By reducing the number of slab sizes across the width, the productivity of the entire converter shop complex — continuous casting machines — is also increased. 1 hp f-ly, 4 ill.

Description

The invention relates to rolling production, and specifically to the manufacture of strips and sheets on wide-strip hot rolling mills with a reversible vertical stand in the roughing group and on reversible sheet mills.

The purpose of the invention is to expand the technological capabilities of the vertical cage and increase the yield of rolled metal by reducing the face cut.

FIG. Figure 1 shows a vertical stand for implementing the method; in fig. 2 is a diagram of the profiling of the front end of the rolls across its width; in fig. 3 - the sequence of operations when profiling the ends of rolls and rolling in a reversible vertical stand; in fig. 4 is a diagram of the vertical stand and transport device used to implement the proposed method.

The length of the edge trim is reduced by profiling the ends of the rolls, which are deformed in a vertical cage with a greater compression than their main part. The profiling of the ends of the roll is produced by flat surfaces of non-rotating locked vertical rolls, and before rolling, only the front end of the roll is rolled along the rolling arc during rolling and compresses it by an amount equal to the total compression of the main part of the roll in width in two subsequent passes. After rolling in the first of these two passes and the reverse of the roll for rolling in the second pass, the front end of the roll becomes the back end and is also profiled because the compression of the main part of the roll in the previous pass was less than the profiling. Thus, the profile when reversing rolling before each pass only the front during the course of rolling end of the roll, get profiled both ends of the roll. This reduces the number of operations.

To obtain the same finished width of the roll along the entire length after the last pass before this pass, the front end of the roll is profiled, crimping it by the amount of reduction of the main part of the roll in the last pass. The selected profiling length, equal to the length of the gripping arc during rolling, provides a rigid, undeformed width across the end that guarantees a straight line shape of the ends of the roll in terms of rolling. Profiling the ends of the roll by flat surfaces of nevrashayuschimi vertical rolls using a pressure device allows you to get a rational shape of the profiled end of the roll and combine the profiling and rolling in one device, namely in the vertical stand, in the roll set of which the barrels have smooth and opposite flat sections.

The vertical reversing cage consists of a bed 1 in which the traverse 2 is mounted with the pressure device 3 and the equilibrium device 4. The traverse 6 is fixed to the traverse 2 by means of the slats 5 with the possibility of vertical movement relative to the roll 7 using the hydraulic cylinder 8 fixed to the traverse 2. On the cassette 6, the pillows 9 of the vertical roll 10 with an elongated neck entering the head of the spindle 11 are fixedly mounted. At the half of the roll barrel 10,

for example, the upper, there is one or more bald faces 12 located along the perimeter of the roll barrel.

In front of the cage there is a lifting roller table 13 with a driving roller table 14 and hydraulic cylinders 15 for lifting.

and lowering the table 13 relative to the roll barrel 10. In the vertical cage, the cushion 9 is fixed motionless directly on the yoke 2.

The diagram (Fig. 2) shows roll 7, the front end of which is profiled at a length of 1 „p between the flats 12, secured against roll forming. 10 with the aid of a pressure device 3, and a retractable stop 16, the position of which can be changed in the direction along the rolling axis in order to regulate the length of the profiling Uf of the front end of the roll 7.

The lifting roller table 13 as well as the retractable stop 16 are shown on one side of the stand with vertical rolls.

0 In fact, they are installed on both sides. The method is carried out as follows.

The moving hot roll 7 is fed to a lifting roller table 13, installed, for example, on the crib side of the cage,

5 and using the hydraulic cylinders 15, raise the table 13 to the level of profiling until the roll 7 is aligned in height with the flats 12 on the barrel of vertical rolls 10. The vertical rolls 10 are set in such a way

0 so dyes 12 were parallel, and the distance between them was not less than the width of the roll. In this position, the rolls 10 are secured against turning with, for example, a brake mounted on a roll drive shaft (not shown). Roll 7 using the drive roller table 14 is fed into the roll gap, formed by the disks 12, up to the stop 16 on the right side of the cage, which position along the rolling axis can be changed to set the required length of the further milling of the front end of the roll Up, and 3, the front end of rollout A (Fig. 3) is crimped by the value of liters V., (step 1). After that, the rolls 10 are diluted, the stop 16 is removed, the table 13 is lowered by means of hydraulic 5 cylinders 15 to align roll 7 in height with the rolling level, turn off the construction of rolls 10 and perform one-pass rolling on the section of rolls with a smooth

barrel, crimping roll width to the value of A Bj, equal to half the value of BI (step 2). Then the roll is reversed, raised to the level of profiling, end-B profiling is performed 3, crimping it by the value of dB (for this purpose lifting table 13 on the right side of the cage and the retracting stop 16 on the left side of the cage are used), lower the roll to the rolling level and rolling in one pass (step 4) with LV compression. Thus, operations 3 and 4 repeat the corresponding operations 1 and 2, and due to the fact that the compression of the front end of the roll when profiling the DW is 2 times more than the compression of IB during rolling, then after the reverse of the roll, when its front end it becomes posterior, it is already profiled. Therefore, profiling operations are performed only at the front end of the roll. Before the last skip, the compression when profiling the front end of the roll (step 5) is chosen equal to the amount of roll cut when rolling in the last pass (step 6) so that the width of the roll after the last pass is the same along the entire length. After the roll has been compressed into a cage with vertical rolls and the required width is obtained, it is transferred to a cage or cage with horizontal rolls to obtain the required thickness.

The proposed method can be carried out in a different way, for which the roll 7 is fed into the cage 1 with a conventional roller conveyor, and the section of the barrel of the rolls 10 with the bevels 12 or the section with the smooth barrel with the roll 7 is combined using hydraulic cylinders 8, lowering or raising the cartridge 6, on which the pillows 9 of the rolls 10 are fastened. In this case, the elongated neck of the rolls 10 moves in the head of the spindle 11, not out of the contact. The remaining operations are similar.

Example. From a slab with dimensions of 200x1400x x2500 mm on a wide-strip hot rolling mill, a strip with dimensions of 2x x1300 mm is obtained. The maximum compression of the roll in the cage with vertical rolls is DVg 40 mm, the diameter of the barrel of the vertical rolls is 1600 mm.

The slab heated in the furnace is fed along the roller table to the lifting table 13, for example, on the left side of the cage and lifts it to the level of profiling. The rolls 10 are set to a position in which the flats 12 are parallel, and the distance between them is at least 1400 mm (i.e., equal to the width of the slab), and in this position the rolls 10 stop from turning. The front end of the slab A is fed into the shed of the rolls, formed by the tracks 12, up to the stop 16, whose position in the direction of the longitudinal axis of the slab

five

d 5 0 0

5 d

five

five

adjusted to the profiling length mm. This value is determined by the formula ar 1d, and 1d yy - d H 180 mm where 1d is the length of the capture arc; R is the radius of the rolls; dB - rolling reduction.

Thereafter, end A is profiled (step 1), crimped to an amount of 4 V, 24 V, 80 mm, and the width of the profiled end becomes equal to BI In-dB 1320 mm. Then the stop 16 is removed, the rolls 10 are diluted, lowered the slab to the rolling level and the lateral edges of the slab are crimped when rolled on a smooth barrel (step 2) by the value d 40 mm. At the same time, the width of the peg B V-L V, 1360 mm

The roll is reversed, fed to the lift table 13 on the right side of the stand, and the end B is compacted in succession with a reduction of D.V., 80 mm (step 3) and the lateral edges of the roll are crimped during rolling with a reduction of D.V. 40 mm (step 4). 1 and 2. At the same time, the width Bj Bt-dB, 1280 mm. Before the last pass, the profile A is again profiled in the same way, but it is crimped only by the value ABt 40 mm (step 5). As a result, the roll is obtained symmetrically profiled at both ends by the amount of reduction in the last pass of the DWG 40 mm (step 6). After this operation, the width of the roll over the entire length is equal to V. 3,180 mm.

The number of passes in a stand with vertical rolls may differ from three, as in this example, and depends on the ratio of the width of the workpiece and the finished strip.

After obtaining a predetermined width of the Bj roll of 1280 mm in stands with vertical rolls (taking into account the broadening during the subsequent rolling, the width of the strip is equal to 1300 mm, the roll is transferred successively to the rough and finishing groups of the wide-strip mill to obtain the specified final tat tire.

The use of the proposed method allows, in comparison with the known method, to increase the productivity of the mill by providing profiling of the ends of rolls instead of a horizontal press in a vertical cage, on which previously only compression of the narrow faces of slabs and rolls was carried out, to reduce the specific metal consumption by 8-10 kg per ton finished rental.

In addition, it becomes possible to reduce the number of slave sizes in width, which provides an increase in the productivity of the complex converter shop - continuous casting machines.

Claims (2)

Claims 1. Method for hot rolling strips and sheets, including end profiling roll through width reduction, crimping the main part of width rolls in a reversible vertical stand on a smooth roll barrel and then rolling it out of thickness in a horizontal stand, characterized in that in order to expand the technological capabilities of the vertical stand and increase the yield of rolled stock by reduction of the edge cut, profiling of the ends of the drying, are compressed by non-rotating rolls of the vertical stand on the section of the length of the gripping arc, and before each skip only the front end of roll is cut in the course of rolling, crimping it by an amount equal to the total compression of the main part of the roll in width in two subsequent passes, and before the last pass - by the amount of reduction in this pass. 2. A method according to claim 1, characterized in that, in order to ensure the profiling of the ends of rolls, on one of the halves of each roll of the vertical stand, additional flat sections are made in the form of bald spots with the length of each flat 1.2-1.5 of the maximum arc length capture when rolling. with Operation 3 Operations 6 Phie.g Operations Step 5 fO CQ Fig.Z one Physical Center